CN115323632B - Sewing machine control method - Google Patents

Abstract

The utility model provides a control method of a sewing machine, which comprises the following steps: a feed lifting mechanism, a presser foot height detection mechanism for detecting the lifting height of the presser foot, a lower feed mechanism and an electric control module are arranged in the sewing machine; pre-storing a presser foot height threshold value in an electronic control module; when the sewing machine independently lifts the presser foot, the electronic control module controls the following steps according to the real-time height of the presser foot: when the real-time height of the presser foot is equal to or greater than the presser foot height threshold, the electronic control module sends an instruction to the lower driving source, the lower driving source acts, and the lower driving source acts on the lifting tooth swinging seat through the lower driving unit to enable the cloth feeding tooth to sink below the upper surface of the needle plate in the sewing machine. In this application, no matter whether it lifts the presser foot manually or lifts the presser foot automatically, as long as the presser foot lifts upwards, the presser foot height detection mechanism detects that the presser foot real-time height has reached the presser foot height threshold value of predetermineeing, and the electronic control module just supplies the actuating source action under control, and the function of supplying under the automatic presser foot of lifting or manual presser foot of lifting is realized.

Description

Sewing machine control method

Technical Field

The utility model relates to a control method of a sewing machine.

Background

At present, the requirements of middle-high end lockstitch sewing machines on the market on feed dog lower supply technology are larger and larger, the feed dog lower supply technology means that the feed dog automatically sinks below a needle plate when a presser foot is lifted and a thread is cut, the feed dog lower supply can facilitate discharging and prevent the feed dog from scraping a sewing material when the presser foot is lifted, and the thread head remained on the sewing material after the thread is cut can be shorter and more stable when the thread is cut. However, when the existing lockstitch sewing machine realizes the lower supply function when the presser foot is lifted, the electronic control module in the sewing machine automatically controls the lower supply according to whether the presser foot lifting driving source (electromagnet or motor) in the presser foot lifting mechanism acts or not, namely, the lower supply when the presser foot is lifted is only applicable to the lockstitch sewing machine capable of automatically lifting the presser foot, but not applicable to the lockstitch sewing machine capable of manually lifting the presser foot, and certain limitations exist.

Disclosure of Invention

In view of the above-described drawbacks of the prior art, an object of the present utility model is to provide a sewing machine control method that seamlessly realizes a down-feed function when automatically lifting a presser foot or manually lifting the presser foot.

In order to achieve the above object, the present utility model provides a sewing machine control method comprising the steps of:

s1, arranging a feed dog lifting mechanism for driving a feed dog to reciprocate up and down, a presser foot lifting mechanism for driving a presser foot to move up, a presser foot height detection mechanism for detecting the lifting height of the presser foot, a lower feed mechanism and an electric control module in a sewing machine;

the lifting tooth mechanism comprises a lifting tooth swinging seat with a first fixed swinging fulcrum, and the angle of the lifting tooth swinging seat determines the tooth height of the sewing machine;

the presser foot lifting mechanism comprises a pressing rod capable of moving up and down in a reciprocating manner, and the presser foot is arranged at the lower end of the pressing rod;

the presser foot height detection mechanism comprises an inductor, and the inductor is in communication connection with the electronic control module;

the lower supply mechanism comprises a lower supply driving source and a lower supply transmission unit connected between the lower supply driving source and the lifting tooth swinging seat, and the lower supply driving source is in communication connection with the electronic control module;

s2, pre-storing a presser foot height threshold value in the electronic control module;

s3, in the operation process of the sewing machine, the presser foot height detection mechanism detects the real-time height of the presser foot and feeds the real-time height of the presser foot back to the electronic control module; when the sewing machine independently lifts the presser foot, the electronic control module performs the following control according to the real-time height of the presser foot:

when the real-time height of the presser foot is smaller than the presser foot height threshold value, the electronic control module does not send an instruction to the lower driving source, and the lower driving source does not act;

when the real-time height of the presser foot is equal to or greater than the presser foot height threshold, the electronic control module sends an instruction to the lower driving source, the lower driving source acts, and the lower driving source acts on the lifting tooth swinging seat through the lower driving unit to enable the cloth feeding tooth to sink below the upper surface of the needle plate in the sewing machine.

Further, the presser foot lifting mechanism further comprises a right lever with a second fixed swinging fulcrum, a presser foot lifting rod, a left lever with a third fixed swinging fulcrum, a presser foot lifting plate and a pressing rod guide frame fixed on the pressing rod, wherein two ends of the presser foot lifting rod are hinged with the right lever and the left lever respectively, the other end of the left lever is hinged with the upper end of the presser foot lifting plate, a lifting hook part is arranged on the presser foot lifting plate, and a connecting protruding part which is clamped with the lifting hook part is arranged on the pressing rod guide frame.

Further, the presser foot lifting mechanism also comprises a hand wrench positioned outside the sewing machine shell and a manual presser foot lifting transmission unit connected between the hand wrench and the pressure bar guide frame.

Further, the presser foot lifting mechanism further comprises a knee rest ejector rod, and the upper end of the knee rest ejector rod is connected with the right lever.

Further, the presser foot lifting mechanism further comprises a presser foot lifting driving source and an automatic presser foot lifting transmission unit connected between the presser foot lifting driving source and the right lever.

Further, the presser foot lifting mechanism further comprises an electronic knee rest assembly, and an induction box in the electronic knee rest assembly is in communication connection with the electronic control module.

Further, the presser foot height detection mechanism further comprises a sensed piece, the sensed piece is fixed to the pressing rod, and the sensor is fixed to the sewing machine shell.

Further, the sensed member is a magnet, and the sensor is a hall sensor.

Further, in the step S1, a thread cutting mechanism for cutting the thread is further configured in the sewing machine, the thread cutting mechanism includes a thread cutting driving source and a moving knife, and the thread cutting driving source is in communication connection with the electronic control module; the sewing machine control method further comprises the following steps:

s4, in the operation process of the sewing machine, when the sewing machine independently cuts threads, the electronic control module sends instructions to the thread cutting driving source and the lower supply driving source, the thread cutting driving source acts to enable the thread cutting mechanism to execute thread cutting, and meanwhile, the lower supply driving source acts to enable the cloth feeding teeth to sink below the upper surface of a needle plate in the sewing machine.

Further, the sewing machine control method further comprises the following steps:

s5, in the operation process of the sewing machine, when the sewing machine cuts the thread and lifts the presser foot, the electronic control module firstly sends instructions to a thread cutting driving source and a lower supply driving source, the thread cutting driving source acts to enable the thread cutting mechanism to execute thread cutting, and meanwhile, the lower supply driving source acts to enable the feed dog to sink below the upper surface of a needle plate in the sewing machine; after the trimming is finished, the electronic control module enables the lower driving source to be kept continuously; and then, the presser foot lifting mechanism acts to move the presser foot upwards.

As described above, the sewing machine control method according to the present utility model has the following advantageous effects:

in this application, when lifting the presser foot, electric control module is according to the height that the presser foot lifted whether need supply the actuating source action down, consequently, no matter lift the presser foot or automatic the presser foot that lifts, as long as the presser foot upwards lifts, the presser foot height detection mechanism detects that the presser foot real-time height has reached the presser foot height threshold value of predetermineeing, electric control module just controls supply the actuating source action down, make through supply down mechanism that feed dog subsides below the upper surface of faller in the sewing machine, the lower supply function when seamless realization automatic lifts the presser foot or manually lifts the presser foot.

Drawings

Fig. 1 and 2 are schematic structural views of a sewing machine according to the present application at different viewing angles.

Fig. 3 and 4 are schematic structural views of the lower feed mechanism, the loose wire linkage mechanism and the tooth height mechanism in different view angles.

Fig. 5 and 6 are schematic structural views of the presser foot lifting mechanism in the present application under different viewing angles.

Fig. 7 is a schematic structural view of a presser foot height detection mechanism in the present application.

FIG. 8 is a control flow chart of the sewing machine control method in the present application.

FIG. 9 is a control logic diagram of the sewing machine of the present application when the sewing machine lifts the presser foot down supply.

Description of element reference numerals

10. Tooth lifting mechanism

11. Lifting tooth swinging seat

12. Lifting shaft

20. Thread loosening mechanism

21. Loose wire lever

211. Driving inclined plane

22. Loose wire thimble

30. Lower supply mechanism

31. Lower supply driving source

311. Lower supply driving part

312. Fixed joint

32. First lower supply connecting rod

33. Second lower supply connecting rod

34. Lower supply crank

341. Support shaft portion

35. Third lower supply connecting rod

40. Loose wire linkage mechanism

41. Stay wire plate

411. Push plate part

42. Stay wire

43. Limit screw

44. Torsion spring

50. Tooth height adjusting mechanism

51. Adjusting knob

52. Adjusting stud

60. Presser foot lifting mechanism

61. Right lever

62. Presser foot lifting pull rod

63. Left lever

631. Loose thread pushing part

64. Lifting plate for lifting presser foot

65. Compression bar guide frame

66. Compression bar

70. Presser foot lifting driving motor

80. Presser foot lifting driving piece

81. Cam surface for reducing presser foot

91. Crank for lifting presser foot

92. Roller for lifting presser foot

93. Push rod for lifting presser foot

110. Wire clamping device

120. Feeding mechanism

121. Feeding swing seat

122. Feeding shaft

130. Needle pitch adjusting mechanism

131. Needle pitch adjusting eccentric wheel

132. Needle pitch adjusting connecting rod

140. Main shaft

150. Fixing support

160. Fixing seat

170. Presser foot height detection mechanism

171. Sensed piece

172. Inductor

173. Connecting seat

Detailed Description

Further advantages and effects of the present utility model will become apparent to those skilled in the art from the disclosure of the present utility model, which is described by the following specific examples.

It should be understood that the structures, proportions, sizes, etc. shown in the drawings are for illustration purposes only and should not be construed as limiting the utility model to the extent that it can be practiced, since modifications, changes in the proportions, or adjustments of the sizes, which are otherwise, used in the practice of the utility model, are included in the spirit and scope of the utility model which is otherwise, without departing from the spirit or scope thereof. Also, the terms such as "upper," "lower," "left," "right," "middle," and "a" and the like are used herein for descriptive purposes only and not for purposes of limitation, and are intended to limit the scope of the utility model as defined by the claims and the relative terms thereof as construed as corresponding to the claims.

The application provides a sewing machine control method, which is used for a flat sewing machine; the sewing machine comprises a machine shell, a main shaft 140 and a main motor; wherein, the shell is not shown in the shell drawing, and the shell comprises an upper shell and a bottom plate which are fixedly connected; the main shaft 140 is rotatably installed in the upper casing; not shown in the main motor diagram, the main motor is fixed on the upper casing, and the motor shaft of the main motor is fixed with the main shaft 140 through a coupling to drive the main shaft 140 to rotate. For convenience of description, in the following embodiments, the axial direction of the main shaft 140 is defined as the left-right direction, and the direction of the main shaft 140 toward the head (i.e., the needle side) of the sewing machine is the left direction, and the direction of the main shaft 140 toward the tail of the sewing machine is the right direction; defining the moving direction of the sewing material as the front direction when the sewing machine is in forward sewing; a direction orthogonal to both the left-right direction and the front-rear direction is defined as an up-down direction.

Further, the sewing machine control method according to the present application includes the steps of:

in step S1, as shown in fig. 1 and 2, a frame, a feed dog fixed to an upper end surface of the frame, a presser foot, a thread clamp 110 mounted on a rear end surface of an upper housing, a feed dog mechanism 10 for driving the feed dog to reciprocate up and down, a presser foot lifting mechanism 60 for driving the presser foot to move up, a presser foot height detecting mechanism 170 for detecting a lifting height of the presser foot, a lower feed mechanism 30, and an electronic control module are arranged in the sewing machine. The tooth lifting mechanism 10 is connected between the main shaft 140 and the rear end of the tooth frame, and the tooth lifting mechanism 10 comprises a tooth lifting shaft 12 extending leftwards and rightwards, a first tooth lifting transmission assembly connected between the main shaft 140 and the tooth lifting shaft 12, and a second tooth lifting transmission assembly connected between the tooth lifting shaft 12 and the tooth frame; the first lifting tooth transmission assembly comprises a lifting tooth eccentric wheel fixed on the main shaft 140, a lifting tooth connecting rod, a first lifting tooth swinging plate, a second lifting tooth swinging plate, a lifting tooth swinging seat 11 with a first fixed swinging fulcrum and a lifting tooth crank fixed on the lifting tooth shaft 12, the upper end of the lifting tooth connecting rod is rotatably sleeved on the periphery of the lifting tooth eccentric wheel, the lower end of the lifting tooth connecting rod, one end of the first lifting tooth swinging plate and one end of the second lifting tooth swinging plate are coaxially hinged through pins extending left and right, the other end of the first lifting tooth swinging plate is hinged with the lifting tooth crank through pins extending left and right, and the other end of the second lifting tooth swinging plate is hinged with the lifting tooth swinging seat 11 through pins extending left and right. The position angle of the lifting tooth swinging seat 11 determines the transmission efficiency of the first lifting tooth transmission component, thereby determining the tooth height of the sewing machine; the tooth height of the sewing machine means: when the feed dog moves to the highest point, the distance between the highest point of the feed dog and the upper surface of the needle plate is the height of the feed dog rising upwards from the needle plate. As shown in fig. 7, the presser foot lifting mechanism 60 includes a presser bar 66 capable of reciprocating up and down, the presser bar 66 is vertically movably inserted into a presser bar cover fixed to an upper housing, and a presser foot is mounted on a lower end of the presser bar 66. The presser foot height detecting mechanism 170 comprises a sensed member 171 fixed to the presser bar 66, and a sensor 172 fixed to the upper casing of the sewing machine, wherein the sensor 172 is in communication connection with the electronic control module. The lower supply mechanism 30 comprises a lower supply driving source 31 and a lower supply transmission unit connected between the lower supply driving source 31 and the lifting tooth swinging seat 11, and the lower supply driving source 31 is in communication connection with the electronic control module.

Step S2, pre-storing a presser foot height threshold in the electronic control module, wherein the presser foot height threshold is a constant, and the numerical value is determined according to experience and actual requirements.

Step S3, in the operation process of the sewing machine, the presser foot height detection mechanism 170 detects the real-time height of the presser foot and feeds the real-time height of the presser foot back to the electronic control module; when the sewing machine independently lifts the presser foot, the electronic control module performs the following control according to the real-time height of the presser foot: A. when the real-time height of the presser foot is smaller than the presser foot height threshold, the presser foot is not lifted upwards or lifted slightly, the electronic control module does not send a command to the lower supply driving source 31, the lower supply driving source 31 does not act, the sewing machine does not execute the lower supply action, the swing action of the lifting teeth is kept in the normal working angle range, and the sewing machine has effective tooth height; B. when the real-time height of the presser foot is equal to or greater than the presser foot height threshold, the presser foot is lifted up to a certain height and is normally lifted, the electronic control module sends a command to the lower driving source 31, the lower driving source 31 acts, and the lower driving source 31 acts on the lifting tooth swinging seat 11 through the lower driving unit to enable the lifting tooth to swing at a lower working angle; in the process, the feed dog sinks below the upper surface of the needle plate in the sewing machine, namely the upper end of the feed dog is flush with the upper surface of the needle plate or the upper end of the feed dog is lower than the upper surface of the needle plate, the feed dog cannot upwards emerge from the needle plate, a lower feed function is realized when the presser foot is lifted, and the feeding is convenient and the scraping of the sewing material is prevented.

In this application, when the sewing machine is realizing lifting the presser foot and supplying down, the electronic control module judges whether need supply the actuating source 31 action down according to the real-time height that the presser foot lifted, consequently, no matter lift the presser foot or lift the presser foot automatically, as long as the presser foot upwards lifts up, and the presser foot height detection mechanism 170 detects that the presser foot real-time height has reached the presser foot height threshold value of predetermineeing, the electronic control module just controls and supplies the actuating source 31 action down, make the feed dog subside below the upper surface of faller in the sewing machine through supplying down mechanism 30, supply down the function under the seamless realization automation lifts the presser foot or manually lifts the presser foot, promote the intelligent level of sewing machine, improve the market competitiveness of sewing machine. Compared with the prior art, the automatic presser foot lifting device has the advantages that lower supply is realized when the presser foot is lifted, and the automatic presser foot lifting device is independent of automatic presser foot lifting.

Further, as shown in fig. 1 and 2, the sewing machine according to the present application is further provided with a feeding mechanism 120 connected between the main shaft 140 and the front end of the frame, a thread cutting mechanism for cutting the thread, and a thread releasing mechanism 20 for driving the thread clamp 110 to release the thread; when the sewing machine is used for normal sewing, the main motor drives the main shaft 140 to rotate, the main shaft 140 drives the feed dog and the feed dog to reciprocate up and down through the feed dog lifting mechanism 10, and the feed dog executes a feed dog lifting action; the spindle 140 drives the tooth rack and the feed tooth to reciprocate back and forth through the feeding mechanism 120, and the feed tooth executes a feed action; so that the feed dog performs the compound motion of up-and-down reciprocating motion and front-and-back reciprocating motion.

Further, as shown in fig. 5 and 6, the presser foot lifting mechanism 60 further includes a right lever 61 having a second fixed swing fulcrum, a presser foot lifting lever 62, a left lever 63 having a third fixed swing fulcrum, a presser foot lifting plate 64, and a presser bar guide 65 fixed to a presser bar 66, both ends of the presser foot lifting lever 62 are hinged to the right lever 61 and the left lever 63, respectively, the other end of the left lever 63 is hinged to the upper end of the presser foot lifting plate 64, a lifting hook portion is provided on the presser foot lifting plate 64, and a connection protrusion engaged with the lifting hook portion is provided on the presser bar guide 65. The left lever 63 and the right lever 61 are both hinged to the upper housing by shaft screws extending forward and backward. The presser foot lifting mechanism 60 with this structure may be a manual presser foot lifting mechanism, an artificial knee presser foot lifting mechanism, an automatic presser foot lifting mechanism, or an electronic knee presser foot lifting mechanism, and these four presser foot lifting mechanisms may be independent or may be combined and coexist.

Specifically, when the presser foot lifting mode is manual presser foot lifting, the presser foot lifting mechanism 60 further comprises a hand wrench positioned outside the upper section casing of the sewing machine, and a manual presser foot lifting transmission unit connected between the hand wrench and the presser bar guide frame 65; the sewing worker rotates the hand wrench, and the hand wrench drives the pressure bar guide frame 65 to move upwards through the manual pressure bar lifting transmission unit, so that the pressure bar 66 and the pressure bar are driven to move upwards, and manual pressure bar lifting is realized; there are various structural forms of the manual presser foot lifting transmission unit, and reference may be made to a manual presser foot lifting mechanism 60 disclosed in the specification of the chinese patent application No. 202020819608.8; or can see a sewing machine presser foot lifting structure disclosed in the specification of China patent application No. 201710815394. X.

When the presser foot lifting mode is artificial knee leaning presser foot lifting, the presser foot lifting mechanism 60 further comprises a knee leaning ejector rod, and the upper end of the knee leaning ejector rod is connected with the right lever 61; the knee of the sewing worker lifts the knee rest push rod upwards to push the right lever 61 to rotate, so that the presser foot is lifted by the artificial knee rest.

When the presser foot lifting mode is automatic presser foot lifting, as shown in fig. 5 and 6, the presser foot lifting mechanism 60 further includes a presser foot lifting drive source, and an automatic presser foot lifting transmission unit connected between the presser foot lifting drive source and the right lever 61; the electronic control module sends an instruction to the presser foot lifting driving source, the presser foot lifting driving source acts, and the automatic presser foot lifting driving unit pushes the right lever 61 to rotate, so that the automatic presser foot lifting is realized.

When the presser foot lifting mode is the electronic knee-rest presser foot lifting mode, the presser foot lifting mechanism 60 further comprises a presser foot lifting driving source, an automatic presser foot lifting transmission unit connected between the presser foot lifting driving source and the right lever 61, and an electronic knee-rest assembly, wherein an induction box in the electronic knee-rest assembly is in communication connection with the electronic control module. The knee of the sewing worker is leaned against the knee leaning disc in the electronic knee leaning assembly and pushes the knee leaning disc, the output signal of the induction box in the electronic knee leaning assembly changes, the electronic control module sends an instruction to the presser foot lifting driving source after identifying, the presser foot lifting driving source acts and pushes the right lever 61 to rotate through the automatic presser foot lifting transmission unit, and the presser foot lifting of the electronic knee leaning assembly is realized. There are various structural forms of the electronic knee rest assembly, and the electronic knee rest triggering structure disclosed in the specification of the Chinese patent application with the application number of 201910233352.4 can be referred to.

Further, in the presser foot height detection mechanism 170, the sensed member 171 is a magnet, and the sensor 172 is a hall sensor. As shown in fig. 7, the presser foot height detecting mechanism 170 further includes a connecting seat 173, the connecting seat 173 is fixedly connected to the upper end of the pressing lever 66, and a magnet is fixed in the connecting seat 173, so that the magnet is fixed to the upper end of the pressing lever 66.

The structure of the thread cutting mechanism is in the prior art, and can be seen from an automatic thread cutting mechanism disclosed in Chinese patent specification of application number 201720338995.1, and the thread cutting mechanism mainly comprises a thread cutting driving source and a movable cutter, wherein the thread cutting driving source is in communication connection with an electronic control module. When the thread cutting mechanism and the presser foot lifting mechanism 60 are simultaneously arranged in the sewing machine, the sewing machine control method further comprises the following steps:

and S4, in the operation process of the sewing machine, when the sewing machine independently cuts threads, the electronic control module sends instructions to the thread cutting driving source and the lower supply driving source 31, the thread cutting driving source acts to enable the thread cutting mechanism to execute thread cutting, meanwhile, the lower supply driving source 31 acts, and the lower supply driving source 31 acts on the lifting tooth swinging seat 11 through the lower supply transmission unit to enable the lifting tooth to swing at a lower supply working angle, and finally the cloth feeding tooth sinks below the upper surface of a needle plate in the sewing machine. Therefore, when the thread cutting mechanism cuts threads, the lower feeding mechanism 30 can execute the lower feeding action, so that the feed dog automatically sinks and does not upwards overflow from the needle plate, and the feed dog does not upwards lift the stitching material, so that the distance between the stitching material and the cutting opening of the thread cutting mechanism is shortened, and the thread cutting effect of the short thread ends is stably realized.

Step S5, when the sewing machine cuts the thread and lifts the presser foot in the operation process of the sewing machine, the electronic control module firstly sends instructions to the thread cutting driving source and the lower driving source 31, the thread cutting driving source acts to enable the thread cutting mechanism to execute thread cutting, meanwhile, the lower driving source 31 acts on the lifting tooth swinging seat 11 through the lower driving unit, the lifting tooth swings to be at a lower feeding working angle, and finally the feed dog sinks below the upper surface of a needle plate in the sewing machine; after the thread is cut, the electronic control module enables the lower supply driving source 31 to keep on, the lower supply driving source 31 enables the lifting teeth to swing through the lower supply transmission unit to keep the lower supply working angle, and the feed teeth are kept below the upper surface of the needle plate; thereafter, the presser foot lifting mechanism 60 operates to move the presser foot upward. In this way, the lower feed and the lower feed of the presser foot can be realized, the use frequency of the lower feed driving source 31 in linkage is reduced, and the service life of the lower feed driving source 31 is prolonged.

Further, the sewing machine has a tooth height adjusting function, a stitch length adjusting function, an automatic thread loosening function during thread cutting and an automatic thread loosening function during presser foot lifting; accordingly, the sewing machine is further provided with a thread releasing linkage mechanism 40, a tooth height adjusting mechanism 50 and a stitch length adjusting mechanism 130; the preferred structure of each functional mechanism in the sewing machine is described below.

As shown in fig. 1 and 2, the feeding mechanism 120 includes a feeding shaft 122 extending left and right, a first feeding transmission assembly connected between the main shaft 140 and the feeding shaft 122, and a second feeding transmission assembly connected between the feeding shaft 122 and a frame in the sewing machine; the first feeding transmission assembly comprises a feeding eccentric wheel fixed on the main shaft 140, a feeding connecting rod, a first feeding swing plate, a second feeding swing plate, a feeding swing seat 121 with a fourth fixed swing pivot and a feeding crank fixed on the feeding shaft 122, wherein the upper end of the feeding connecting rod is rotatably sleeved on the periphery of the feeding eccentric wheel, the lower end of the feeding connecting rod, one end of the first feeding swing plate and one end of the second feeding swing plate are coaxially hinged through pins extending left and right, the other end of the first feeding swing plate is hinged with the feeding crank through pins extending left and right, and the other end of the second feeding swing plate is hinged with the feeding swing seat 121 through pins extending left and right. The position angle of the feeding swing seat 121 determines the transmission efficiency of the first feeding transmission assembly, thereby determining the needle pitch of the sewing machine.

As shown in fig. 1 and 2, the thread releasing mechanism 20 comprises a thread releasing lever 21 and a thread releasing thimble 22 for driving the thread clamp 110 to perform thread releasing action, wherein the thread releasing lever 21 is hinged to an upper casing of the sewing machine through a shaft position screw extending forwards and backwards, so the thread releasing lever 21 is provided with a fifth fixed swinging fulcrum, and the thread releasing lever 21 is provided with a driving inclined plane 211 in contact fit with the thread releasing thimble 22; when the thread releasing lever 21 rotates around the fifth fixed swing fulcrum, the driving inclined plane 211 on the thread releasing lever 21 can push the thread releasing thimble 22 to move backwards, so that the thread releasing thimble 22 is inserted into the thread clamp 110, the thread clamp 110 executes thread releasing action, and automatic thread releasing of the thread clamp 110 is realized. The thread loosening mechanism 20 further comprises a pre-tightening spring acting on the thread loosening lever 21, and the driving inclined surface 211 of the thread loosening lever 21 is always attached to the thread loosening thimble 22 under the action of the spring force exerted on the thread loosening lever 21 by the pre-tightening spring.

As shown in fig. 3 and 4, the wire releasing linkage 40 includes a wire drawing plate 41 having a sixth fixed swing fulcrum and in driving engagement with the lower driving source 31, and a wire drawing 42 connected between the wire drawing plate 41 and the wire releasing lever 21 in the wire releasing mechanism 20. When the sewing machine is normal, the lower driving source 31 does not act, the lifting teeth swing action is kept in the normal working angle range, and the sewing machine has effective tooth height. When the thread is needed to be cut or the presser foot is lifted, the lower driving source 31 acts, and the lower driving source 31 acts on the lifting tooth swinging seat 11 through the lower driving unit to enable the feed dog to sink below the upper surface of the needle plate in the sewing machine; meanwhile, the lower driving source 31 also drives the stay wire plate 41 to rotate around the sixth fixed swinging fulcrum, the stay wire plate 41 pulls the loose wire lever 21 to rotate around the sixth fixed swinging fulcrum through the stay wire 42, the driving inclined plane 211 on the loose wire lever 21 pushes the loose wire thimble 22 to move backwards, and the loose wire thimble 22 is inserted into the wire clamp 110 backwards, so that the wire clamp 110 executes the loose wire action, and automatic loose wire of the wire clamp 110 during cutting and automatic loose wire during lifting of the presser foot are realized. When the thread is cut, the thread can be automatically loosened, so that the thread end is prevented from rebounding and falling off after the thread is cut due to the fact that the upper thread is too tight and straight; when the presser foot is lifted, the automatic thread loosening can prevent the user from excessively tightening the upper thread, and the thread drawing is easier. The application uses the same lower supply driving source 31 to realize the function of automatically loosening the thread of the thread clamp 110 when automatically supplying and cutting the thread, reduces the production cost of the sewing machine, improves the intelligent level of the sewing machine, and improves the market competitiveness of the product.

Preferably, as shown in fig. 3 and 4, the lower driving source 31 has a lower driving part 311 that can extend and retract up and down; based on this, the lower driving source 31 may be selected from a linear motor, an electromagnet, a cylinder, and the like. In this embodiment, the lower driving source 31 is an electromagnet, the lower end of the iron core of the electromagnet is connected with a fixed joint 312 in a threaded manner, and the iron core of the electromagnet and the fixed joint 312 together form the lower driving portion 311. When the sewing machine does not need a lower supply function, the electromagnet is in a power-off state; when the sewing machine needs a lower feed function in the process of lifting the presser foot and cutting the thread, the electromagnet is electrified, the iron core of the electromagnet moves downwards, the fixed joint 312 moves downwards along with the iron core, and the lower feed transmission unit acts on the lifting tooth swinging seat 11 to enable the cloth feeding tooth to automatically descend; meanwhile, the iron core of the electromagnet pushes the stay wire plate 41 to rotate, so that the wire loosening mechanism 20 is driven to act, and the wire clamping device 110 is loosened. In addition, the sewing machine further comprises a fixing bracket 150 fixed to the upper casing, and the lower driving source 31 is fixedly mounted on the fixing bracket 150 through a plurality of screws, so that the lower driving source 31 is fixedly mounted on the upper casing.

Further, as shown in fig. 3 and 4, the stay plate 41 is hinged to the upper casing by a front-rear extending axial screw which constitutes a sixth fixed swing fulcrum of the stay plate 41. The pulling wire plate 41 is provided with a pushing plate part 411 which extends horizontally and is positioned right below the lower driving part 311, and the pushing plate part 411 is positioned at the left side of the sixth fixed swinging fulcrum of the wire loosening plate and is arranged in a dislocation manner. When the lower driving source 31 is operated, the lower driving portion 311 moves downward, the fixed joint 312 is in abutting engagement with the push plate portion 411, and the push plate portion 411 is pushed downward along with the continued downward movement of the electromagnet core and the fixed joint 312, so that the wire pulling plate 41 is driven to rotate about the sixth fixed swing fulcrum thereof. Preferably, the stay wire 42 is a flexible stay wire, one end of the stay wire 42 is fixedly connected with the stay wire plate 41 through two nuts, and the other end of the stay wire 42 is riveted on the wire loosening lever 21.

Preferably, as shown in fig. 3 and 4, the thread loosening linkage mechanism 40 further includes a limit screw 43 fixed on the inner wall of the upper casing of the sewing machine, and a torsion spring 44 sleeved on the sixth fixed swing fulcrum of the thread loosening plate, wherein two ends of the torsion spring 44 are respectively connected with the upper casing and the thread loosening plate, the thread loosening plate 41 is provided with a plate limit part below the limit screw 43, and the torsion spring 44 applies an upward acting force to the thread loosening plate 41. When the lower driving source 31 is not operated, the plate stopper portion of the wire drawing plate 41 is abutted against the stopper screw 43 by the spring force of the torsion spring 44, and the wire drawing plate 41 is stably held at a fixed position by the torsion spring 44 and the stopper screw 43. After the lower driving source 31 is operated, the iron core of the electromagnet and the fixed joint 312 push the pull wire plate 41 to rotate downwards, overcoming the spring force of the torsion spring 44. After the lower power supply driving source 31 is reset from the power-on state to the power-off state, the torsion spring 44 drives the stay wire plate 41 to rotate upwards until the stay wire plate 41 is abutted with the limit screw 43, and also drives the iron core of the electromagnet and the fixed joint 312 to move upwards and reset.

Further, the preferable structure of the lower power transmission unit is: as shown in fig. 3 and 4, the lower feed transmission unit includes a first lower feed link 32, a second lower feed link 33, a lower feed crank 34 having a seventh fixed swing fulcrum, and a third lower feed link 35, the upper end of the first lower feed link 32 is hinged with a fixed joint 312, the lower end of the first lower feed link 32 is hinged with one end of the second lower feed link 33, the other end of the second lower feed link 33 is fixed with the lower feed crank 34 through a nut and a short pin, and the upper and lower ends of the third lower feed link 35 are respectively hinged with the lower feed crank 34 and the lifting swing seat 11. The third lower feed link 35, the lower feed crank 34 and the lifting-tooth swinging seat 11 are mutually hinged to form a four-bar linkage together. A supporting shaft portion 341 integrally extends rightward from the right end surface of the lower supply crank 34, and the supporting shaft portion 341 is rotatably supported in the upper casing through a boss, so that the supporting shaft portion 341 constitutes a seventh fixed swing fulcrum of the lower supply crank 34. The lower supply mechanism 30 is an independent module and can be opened and closed according to the model and the requirement.

Further, the tooth height adjustment mechanism 50 is preferably structured as follows: as shown in fig. 3 and 4, the tooth height adjusting mechanism 50 includes an adjusting knob 51 rotatably mounted to an upper casing of the sewing machine, and an adjusting stud 52 screwed into the upper casing and extending forward and backward, the rear end of the adjusting stud 52 being fixed to the adjusting knob 51, the front end of the adjusting stud 52 being in abutting engagement with the lower supply crank 34. The adjusting knob 51 is rotated to drive the adjusting stud 52 to move in the front-rear direction, so that the lower supply crank 34 is driven to rotate around the seventh fixed swing fulcrum, the lower supply crank 34 acts on the lifting tooth swing action through the third lower supply connecting rod 35, the normal working angle of the lifting tooth swing action is changed, the effective tooth height of the sewing machine is changed, different sewing requirements are met, and the adjustment of the tooth height is realized.

Further, as shown in fig. 5 and 6, the presser foot lifting driving source is a presser foot lifting driving motor 70 and is fixedly mounted on the upper casing, the automatic presser foot lifting transmission unit includes a presser foot lifting driving member 80 fixed on a motor shaft of the presser foot lifting driving motor 70, a presser foot lifting crank 91 having an eighth fixed swinging fulcrum, a presser foot lifting roller 92 rotatably mounted on the presser foot lifting crank 91, and a presser foot lifting push rod 93, the presser foot lifting driving member 80 is a cam member, the outer peripheral surface thereof has a presser foot lifting reducing cam surface 81, the lower end of the presser foot lifting push rod 93 is hinged with the presser foot lifting crank 91, and the upper end of the presser foot lifting push rod 93 is hinged with the right lever 61 in the presser foot lifting mechanism 60. Preferably, the sewing machine further includes a fixing base 160 fixed to the upper casing, the presser foot lifting crank 91 is hinged to the fixing base 160 by a pin extending from left to right, and a hinge point of the presser foot lifting crank 91 and the fixing base 160 forms an eighth fixed swing fulcrum of the presser foot lifting crank 91. As shown in fig. 1 and 2, the stitch length adjusting mechanism 130 includes a stitch length adjusting eccentric 131 fixed on a motor shaft of the presser foot lifting driving motor 70, and a stitch length adjusting link 132, the upper end of the stitch length adjusting link 132 is rotatably sleeved on the outer circumference of the stitch length adjusting eccentric 131, and the lower end of the stitch length adjusting link 132 is hinged with the feeding swing seat 121.

Further, in the range that the motor shaft of the presser foot lifting driving motor 70 rotates for 360 degrees, at least the corner of the motor shaft of the presser foot lifting driving motor 70 is provided with a presser foot lifting corner region and a stitch length adjusting corner region, and the presser foot lifting corner region and the stitch length adjusting corner region are in two mutually independent ranges. When the sewing machine works normally, the motor shaft of the presser foot lifting driving motor 70 outputs a turning angle value in the stitch-adjusting corner area, and the sewing machine has an effective stitch. When the needle pitch is required to be adjusted, the motor shaft of the presser foot lifting driving motor 70 rotates in a needle pitch adjusting corner region, another corner value in the needle pitch adjusting corner region is output, the feeding swing seat 121 is driven to rotate around a fourth fixed swing fulcrum through the needle pitch adjusting eccentric wheel 131 and the needle pitch adjusting connecting rod 132, and the angle of the feeding swing seat 121 is changed, so that the needle pitch of the sewing machine is changed; in this process, the presser foot lifting roller 92 is in contact fit with the constant diameter surface of the outer periphery of the presser foot lifting driving member 80, or the presser foot lifting roller 92 is separated from the presser foot lifting driving member 80, so that no power is transmitted between the presser foot lifting roller 92 and the presser foot lifting driving member 80, the right lever 61 does not rotate, and the presser foot keeps the current state. When the presser foot is required to be automatically lifted, the motor shaft of the presser foot lifting driving motor 70 rotates from the current corner in the stitch-adjusting corner region to the presser foot lifting corner region, when the motor shaft of the presser foot lifting driving motor 70 runs in the presser foot lifting corner region, the presser foot lifting roller 92 is in abutting fit with the presser foot lifting reducing cam surface 81 of the presser foot lifting driving member 80, the presser foot lifting reducing cam surface 81 of the presser foot lifting driving member 80 pushes the presser foot lifting roller 92 to drive the presser foot lifting crank 91 to rotate around an eighth fixed swinging fulcrum, the right lever 61 pulls the right lever 61 to rotate around a second fixed swinging fulcrum thereof through the presser foot lifting ejector rod 93, the presser foot lifting pull rod 62 is pulled to the right, the left lever 63 is driven to rotate around a third fixed swinging fulcrum thereof, and the presser foot lifting plate 64 is pulled upwards, so that the presser foot guide frame 65, the presser foot 66 and the presser foot are driven to move upwards together, and the presser foot is automatically lifted after the sewing is finished; meanwhile, the electromagnet forming the lower supply driving source 31 is electrified, and the lower supply transmission unit drives the lifting tooth swinging seat 11 to rotate, so that the cloth feeding teeth sink below the upper surface of a needle plate in the sewing machine, and the lower supply function is realized when the presser foot is lifted, thereby facilitating discharging and preventing the cloth feeding teeth from scraping the seam material; and, the fixed joint 312 of the electromagnet also pushes the stay wire plate 41 to rotate, and the stay wire 42 pulls the loose wire lever 21, so that the loose wire thimble 22 is inserted into the wire clamping device 110 backwards, the wire clamping device 110 executes the loose wire action, the wire clamping device 110 automatically loosens the wire when the presser foot is lifted, the user can not pull the wire too tightly, and the wire drawing is easy. After the presser foot is lifted, the motor shaft of the presser foot lifting driving motor 70 rotates to the inside of the stitch-adjusting corner area and resets.

Preferably, as shown in fig. 1, the left lever 63 is provided with a loose wire pushing part 631; when the presser foot lifting mechanism 60 is operated, the loose thread pushing portion 631 on the left lever 63 moves rightward in a direction approaching the loose thread lever 21, so that the loose thread pushing portion 631 on the left lever 63 contacts and cooperates with the loose thread lever 21 to push the loose thread lever 21 rightward, thereby driving the loose thread lever 21 to rotate around the fifth fixed swing fulcrum and further pushing the loose thread thimble 22 to move backward, and realizing automatic loose thread of the thread clamp 110 when the presser foot is lifted automatically.

In summary, the present utility model effectively overcomes the disadvantages of the prior art and has high industrial utility value.

The above embodiments are merely illustrative of the principles of the present utility model and its effectiveness, and are not intended to limit the utility model. Modifications and variations may be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the utility model. Accordingly, it is intended that all equivalent modifications and variations of the utility model be covered by the claims, which are within the ordinary skill of the art, be within the spirit and scope of the present disclosure.

Claims (10)

1. A sewing machine control method is characterized in that: the sewing machine control method comprises the following steps:

s1, arranging a feed dog lifting mechanism (10) for driving a feed dog to reciprocate up and down, a presser foot lifting mechanism (60) for driving a presser foot to move up, a presser foot height detection mechanism (170) for detecting the lifting height of the presser foot, a lower feed mechanism (30) and an electric control module in the sewing machine;

the lifting tooth mechanism (10) comprises a lifting tooth swinging seat (11) with a first fixed swinging fulcrum, and the angle of the lifting tooth swinging seat (11) determines the tooth height of the sewing machine;

the presser foot lifting mechanism (60) comprises a pressing rod (66) capable of moving up and down in a reciprocating manner, and the presser foot is arranged at the lower end of the pressing rod (66);

the presser foot height detection mechanism (170) comprises an inductor (172), and the inductor (172) is in communication connection with the electronic control module;

the lower supply mechanism (30) comprises a lower supply driving source (31) and a lower supply transmission unit connected between the lower supply driving source (31) and the lifting tooth swinging seat (11), and the lower supply driving source (31) is in communication connection with the electronic control module;

s2, pre-storing a presser foot height threshold value in the electronic control module;

s3, in the operation process of the sewing machine, the presser foot height detection mechanism (170) detects the real-time height of the presser foot and feeds the real-time height of the presser foot back to the electronic control module; when the sewing machine independently lifts the presser foot, the electronic control module performs the following control according to the real-time height of the presser foot:

when the real-time height of the presser foot is smaller than the threshold value of the height of the presser foot, the electronic control module does not send an instruction to the lower supply driving source (31), and the lower supply driving source (31) does not act;

when the real-time height of the presser foot is equal to or greater than the presser foot height threshold, the electronic control module sends an instruction to the lower driving source (31), the lower driving source (31) acts, and the lower driving source (31) acts on the lifting tooth swinging seat (11) through the lower driving unit to enable the cloth feeding teeth to sink below the upper surface of the needle plate in the sewing machine.

2. The sewing machine control method according to claim 1, wherein: the presser foot lifting mechanism (60) further comprises a right lever (61) with a second fixed swinging fulcrum, a presser foot lifting rod (62), a left lever (63) with a third fixed swinging fulcrum, a presser foot lifting plate (64) and a pressure rod guide frame (65) fixed on a pressure rod (66), two ends of the presser foot lifting rod (62) are hinged with the right lever (61) and the left lever (63) respectively, the other end of the left lever (63) is hinged with the upper end of the presser foot lifting plate (64), a lifting hook part is arranged on the presser foot lifting plate (64), and a connecting protruding part which is clamped with the lifting hook part is arranged on the pressure rod guide frame (65).

3. The sewing machine control method according to claim 2, wherein: the presser foot lifting mechanism (60) further comprises a hand wrench positioned outside the sewing machine shell and a manual presser foot lifting transmission unit connected between the hand wrench and the pressure bar guide frame (65).

4. The sewing machine control method according to claim 2, wherein: the presser foot lifting mechanism (60) further comprises a knee rest ejector rod, and the upper end of the knee rest ejector rod is connected with the right lever (61).

5. The sewing machine control method according to claim 2, wherein: the presser foot lifting mechanism (60) further comprises a presser foot lifting driving source and an automatic presser foot lifting transmission unit connected between the presser foot lifting driving source and the right lever (61).

6. The sewing machine control method according to claim 5, wherein: the presser foot lifting mechanism (60) further comprises an electronic knee rest assembly, and an induction box in the electronic knee rest assembly is in communication connection with the electronic control module.

7. The sewing machine control method according to claim 1, wherein: the presser foot height detection mechanism (170) further comprises a sensed piece (171), the sensed piece (171) is fixed to the pressing rod (66), and the sensor (172) is fixed to the sewing machine shell.

8. The sewing machine control method according to claim 7, wherein: the sensed member (171) is a magnet, and the sensor (172) is a hall sensor.

9. The sewing machine control method according to claim 1, wherein: in the step S1, a thread cutting mechanism for cutting the thread is further configured in the sewing machine, the thread cutting mechanism includes a thread cutting driving source and a moving knife, and the thread cutting driving source is in communication connection with the electronic control module; the sewing machine control method further comprises the following steps:

s4, in the operation process of the sewing machine, when the sewing machine independently cuts threads, the electronic control module sends instructions to the thread cutting driving source and the lower supply driving source (31), the thread cutting driving source acts to enable the thread cutting mechanism to execute thread cutting, and meanwhile, the lower supply driving source (31) acts to enable the cloth feeding teeth to sink below the upper surface of a needle plate in the sewing machine.

10. The sewing machine control method according to claim 9, wherein: the sewing machine control method further comprises the following steps:

s5, in the operation process of the sewing machine, when the sewing machine cuts the thread and lifts the presser foot, the electronic control module firstly sends instructions to a thread cutting driving source and a lower supply driving source (31), the thread cutting driving source acts to enable a thread cutting mechanism to cut the thread, and meanwhile, the lower supply driving source (31) acts to enable a cloth feeding tooth to sink below the upper surface of a needle plate in the sewing machine; after the trimming is finished, the electronic control module enables the lower driving source (31) to continue to be kept; then, the presser foot lifting mechanism (60) acts to move the presser foot upward.

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